An esthetically pleasing effect is produced in a multidoor cabinet structure by positioning slab cabinet doors in proximity so that only a very narrow gap or reveal exists between the closed doors. The effect is heightened when the doors are veneered with contiguous components of common facing materials. Such a cabinet structure requires concealed hinges. Moreover, the hinges must mount the doors in such manner that the doors never infringe upon the space occupied by the adjacent door. Quadrilateral linkages are known to achieve this result. Two elements of the quadrilateral are hinge leaves attached respectively to the door and the frame. Two other small links between the hinge leaves complete the linkage structure.
One known quadrilateral hinge structure incorporates a detent-like latch that requires a positive effort on the part of the user in order to operate. Far more acceptable is an arrangement in which spring means incorporated in the hinge itself positively closes the cabinet door without requiring such positive effort.
This known quadrilateral hinge structure, like many hinge structures, does not include a stop to limit opening movement of the cabinet door. The unjustified assumption is made that excessive opening will not be exerted. But, forces are often unintentionally exerted on the linkage. The forces are high due to the very high force multiplication resulting from the small distances to the hinge pivot point as compared with the door width. To incorporate a stop requires the use of massive and exceedingly strong structures. Even if the hinge itself can withstand the high cranking forces, the mounting of the hinge leaves may fail.
The primary object of the present invention is to provide an improved quadrilateral hinge structure for concealed contiguous mounting of slab doors.